Thanks JB, documenting the current extension mechanisms and limitations is useful. Before introducing an Entity SPI, I’d like to understand a concrete use case that requires a new entity type and why the existing extension points are insufficient. Entity types interact with authorization, persistence, and other core semantics, so making them extensible has broader implications than replacing an enum. I’d prefer to work through those requirements first and introduce the smallest extension point they justify, rather than generalize the type system for hypothetical downstream needs.
Yufei On Tue, Oct 13, 2026 at 3:03 PM Dmitri Bourlatchkov <[email protected]> wrote: > > Hi JB, > > This is the kind of question, that, I believe, will come up more and more > often in the future. So, I think it is a good idea to allow extending the > Polaris type system. It will be in line with OO design principles. > > As for specific changes required for that, I do not have anything on my > side, but if anybody has concrete reviewable changes - contributions are > welcome. > > Cheers, > Dmitri. > > On Tue, Oct 13, 2026 at 3:55 AM Jean-Baptiste Onofré <[email protected]> > wrote: > > > Hi folks, > > > > During Lakehouse Day/CommunityOverCode here in Glasgow, several Polaris > > users shared their experiences with building custom Polaris servers and > > adding extensions. > > > > While certain components like Authorizer and Event are straightforward to > > extend (by providing a module with a Jandex index and repackaging), > > creating custom entities is significantly more difficult. Currently, users > > have to modify Polaris core code, essentially adding their custom entities > > directly to the entities enum. > > > > I have created a PR to document the current state of extensions and custom > > entities in Polaris: https://github.com/apache/polaris/pull/5776 > > > > To open a broader community discussion: what can we do to improve the > > developer experience for extending and customizing Polaris? Should we > > consider introducing an "Entity SPI" at some point? > > > > I would love to get your thoughts on this. > > > > Thanks! > > > > Regards, > > JB > >
